1. Field of the Invention
The present invention relates to silver halide light-sensitive materials and particularly to silver halide light-sensitive materials wherein latent image fading is inhibited.
2. Description of the Prior Art
It is well known that two processes, that is, image exposure for forming latent images and development for converting the latent images into silver images or dye images are required for obtaining images with a silver halide photographic process (refer to, for example, C.E.K. Mees & T.H. James, The Theory of the Photographic Process Macmillan & Co.). Formation of the latent image by exposure to light is caused by a minute chemical change of silver halide crystals (refer to Mees & James, supra) and the latent image itself is essentially unstable. Accordingly, the latent image has the property that it easily fades away with the lapse of time between image exposure and development. Such fading of the latent image is called latent image fading. Latent image fading is generally influenced by the storage conditions of the exposed photosensitive material. For example, fading is observed to a great extent at high temperature storage and is observed to a lesser extent at low temperature storage.
The simplest method for avoiding the disadvantage caused by latent image fading comprises carrying out development immediately after exposure to light. A second simple method comprises cooling the exposed photosensitive material and storing it at a low temperature for the time period between image exposure and development processing. Although these methods are the easiest solutions from a chemical viewpoint, when the convenience of users is considered it is difficult to say that they are preferred solutions. From a practical standpoint, photographic negative materials and photographic reversal materials are often left at room temperature for several months between image exposure and development processing, and positive materials for duplication are sometimes left for a few days.
For the above described reason, the production of photosensitive materials wherein latent image fading is inhibited by a specific means at preparation of silver halide photosensitive materials is desired, and thus many methods have been attempted hitherto. However, as the result of detailed studies it has been found the use of hydroxyl group substituted aromatic compounds as described in German Patent No. 1,107,508, 1,3-diones as described in U.S. Pat. No. 3,447,926 or nitrilotriacetic acid as described in U.S. Pat. No. 3,318,702, the process described in U.S. Pat. No. 3,424,583 and the process described in German Patent No. 1,173,339 are all insufficient to attain such an object.